In movable equipments such as passenger planes, drainage pipes are installed for a sink and a toilet in a lavatory. During use of the drainage pipes, calcium compounds and organic compounds are deposited in the drainage pipes (the deposit is hereinafter referred to as “scale”). Since the scale thus deposited may cause the reduction of the draining capacity, the clogging of the pipes and an offensive smell, the scale should periodically be removed.
A conventional method for the removal of the scale is such that the drainage pipes are detached from the movable equipment, transported to a site equipped with a special cleaning apparatus for cleaning the drainage pipes, transported back to the movable equipment after completion of the cleaning, and attached to the movable equipment.
The movable equipment has a complicated inner structure, and the drainage pipes are bent in various directions. Therefore, the drainage pipe detaching and attaching operations are very difficult, requiring enormous amounts of time, efforts and costs. For this reason, a drainage pipe cleaning operation is performed only in a regular maintenance operation. Since the scale is gradually deposited in the drainage pipes, reduction in draining capacity and sudden clogging of the drainage pipes may occur before the next regular maintenance operation.
Accordingly, there is a great demand for development of a system for cleaning a drainage pipe in a short time without detaching the drainage pipe.
It is an object of the present invention to provide a system for cleaning a drainage pipe in a short time for removal of scale without detaching the drainage pipe from movable equipment.